下列选项中,不属于暴风雪天气具备的条件的是( )。
In writing, which step is used to get students to think freely and put down all possible ideas related to the topic that come to their minds?
张衡是我国东汉时期伟大的天文学家、数学家、发明家、地理学家、文学家,下图是张衡发明的仪器,它的用途是( )。
